Non-contact passive temperature measuring system and method of operation using micro-mechanical sensors

A non-contact passive infrared (IR) thermometer for remote temperature measurement of a remote target, comprising:

• a) a cantilevered spring element having a region treated with a material that absorbs a specified spectral region of infrared radiation and exhibits a physical change in response to absorbing the specified spectral region of infrared radiation;
• b) collection means for collecting and directing at least a portion of the incoming IR from the target onto the treated region of the spring element;
• c) deflection detection means for detecting a deflection of the cantilevered spring element due to bimaterial effect as the treated region of the spring element absorbs infrared radiation and exhibits the physical change;
• and
• d) processor means for determining the target thermal energy in at least two different spectral regions;
• said processor means further determining the temperature of the target from calculating a ratio of the thermal power in the different spectral regions,
• whereby the target temperature is independent of the target size, emissivity, and distance to the detector.

Apparatus for non-contact remote temperature measurement of a target, comprising:

• a) collection means collecting and focusing incoming infrared radiation (IR) from the target on an IR detector;
• b) said IR detector means including a piezoelectric transducer having at least one cantilevered spring element secured thereto, said spring element having a first area coated with a first material having an affinity for IR in a first spectral region;
• said spring element having a second area coated with a second material having an affinity for IR in a second spectral region;
• c) oscillator means for stimulating said transducer at or about a resonant vibrational frequency of said cantilevered spring and providing a first output vibrational frequency change indicative of the IR radiation in a first spectral region absorbed by the first material;
• said oscillator means providing a second output vibrational frequency change indicative of the IR radiation in a second spectral region absorbed by the second material;
• d) processor means responsive to the first and second vibrational frequency changes for determining the target thermal energy in the two different spectral regions;
• and
• e) said processor means further determining the temperature of the target from calculating a ratio of the thermal power in the different spectral regions whereby the target temperature is independent of the target size, emissivity and distance to the detector.

A method for remote measurement of the temperature of a target independent of target size, target distance and emissivity, comprising the steps of:

• a) collecting and focusing incoming IR from a target onto an IR detector means;
• b) measuring thermal energy of the target over a spectrum using the IR detector means;
• c) determining the target thermal energy in at least two different spectral regions;
• and
• d) determining the temperature of the target by calculating a ratio of the thermal power in the different spectral regions, whereby the target temperature is determined independent of the target size, emissivity and distance to the detector.

A method for determining temperature of a target independent of target size, target distance, and emissivity, comprising the steps of:

• a) providing a cantilevered spring element having a structural secured to a piezoelectric transducer, said spring element having a surface coated in a first defined region with a radiation absorptive material in a first IR spectral range and coated in a second defined region with a radiation absorptive material in a second IR spectral range;
• b) electrically driving said transducer at or near a resonance frequency of said spring element;
• c) collecting and focusing incoming IR from the target on one of the first or second defined regions;
• d) measuring changes in resonant frequency of the transducer due to the absorptive qualities of the radiation absorptive materials in the first and second defined regions;
• e) determining the target thermal energy in at least two different spectral regions from the changes in resonant frequency of the transducer;
• and
• f) determining the temperature of the target by calculating a ratio of the thermal power in the different spectral regions, whereby the target temperature is determined independent of the target size, emissivity, and distance to the detector.

A non-contact infrared (IR) thermometer for remote temperature measurement of a remote target over a wavelength spectrum, comprising:

• a) a microcantilever;
• b) a first radiation absorptive member formed on the microcantilever and exhibiting a physical change when exposed to radiation over a first wavelength range;
• c) a second radiation absorptive member formed on the microcantilever and exhibiting a physical change when exposed to radiation over a second wavelength range;
• d) means for collecting and focusing IR radiation from a target onto each of the first and second radiation absorptive members;
• e) means for generating sensor signals representative of physical changes in each of the first and second radiation absorptive members;
• f) signal transducer means for translation of the sensor signals into binary form;
• g) processing means providing an output by ratioing the sensor signals over two or more different wavelength bands;
• and
• h) means for determining the temperature of the target from the output of the processing means.